Jean-Louis Gassée, on the widespread expectation that year-over-year iPad sales have leveled off:

Despite the inspiring ads, Apple’s hopes for the iPad overshot
what the product can actually deliver. Although there’s a large
numbers of iPad-only users, there’s also a substantial population
of dual-use customers for whom both tablets and conventional PCs
are now part of daily life.

I see the lull in iPad sales as a coming down to reality after
unrealistic expectations, a realization that iPads aren’t as ready
to replace PCs as many initially hoped.

In short, Gassée is arguing that tablet sales have hit a wall, and that the iPad needs to grow more Mac-like capabilities for advanced tasks.

Posit: slow iPad sales are worse news for the PC market: implies
phones can take the greater share of PC use cases.

I find that compelling. We might have overestimated the eventual role of tablets and underestimated the role of phones — and the whole argument is further muddled by the industry-wide move toward 5-inch-ish phone displays.